Rotating Water-Cooled Beryllium Target for a Compact Neutron Source

Abstract

With the declining number of neutron sources in the world and the decommissioning of research reactors, projects to develop compact neutron sources are attracting more and more attention. The DARIA project suggests the use of a proton beam accelerated to an energy of 13 MeV, which, hitting a beryllium target, creates a neutron beam through the a nuclear reaction (p, n). The reaction yield is three neutrons per 1000 protons, so in this process most of the proton beam energy is released as heat in the target. Intense heating of a beryllium target in the absence of sufficient heat removal can lead to its destruction. A system has been developed for efficient heat removal from a beryllium target during its irradiation with a proton beam. It is a rotating water-cooled beryllium target and is capable of removing a large thermal power from the inner (water-side) surface of the target. For the proposed system, numerical simulations of the speed and pressure of the coolant were carried out. The limiting pressure leading to the destruction of the target and the flows corresponding to this limiting pressure were calculated. Thermodynamical simulations allowed us to evaluate both the average temperature of the system and the peak local (caused by short high-energy pulses) temperatures.